Systematic analysis of Halobacterium sp. NRC-1 heat shock protein genes

• Main Authors: Ping-Liang Hung, 洪秉良
• Other Authors: Wailap Victor Ng
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/96831780776316466568

碩士 === 國立陽明大學 === 醫學生物技術研究所 === 94 === Heat shock response is a highly conserved mechanism to promote the survival of cells upon environmental change. The regulatory mechanism has been well studied in bacteria and eukaryotes but not in the domain archaea. In this study, Halobacterium sp. NRC-1 is served as a model system to better understand the heat shock system in archaea. We combined computation analyses and Northern blot hybridization assays to analyze and discover heat shock protein genes in this species. The upstream sequences of the annotated NRC-1 heat shock protein genes were analyzed for conserved motif sequences. Using the GCG findpatterns program to search NRC-1 genome for a putative upstream heat shock regulator sequence, we found 104 HSP candidate genes. Among these are twenty-six genes of known function, twenty conserved hypothetical protein genes, and fifty-eight hypothetical protein genes. We verified the up regulation of hsp1 and cctA upon culture temperature increases by Northern blot hybridization. On the contrary, the expression of lon decreased by approximately 2.5 times in the same conditions. Interestingly the expression of 3 computation predicted heat shock responsive genes vng0208h, vng0906h, vng1297c were obviously decreased when the cells were cultured at a higher temperature. The observations of the absence of highly conserved upstream sequence(s) among all of the annotated hsp genes and the variable expression patterns upon temperature shifts suggested heat shock response is a complex system in the domain archaea. Thus the regulatory mechanism and the system components have yet to be discovered by additional analyses.